Rock-drill.



M. SMITH.

ROCK DRILL.

APPLICATION FILED SEPT- 28. 1916.

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I ATTORNEYS F Patented July 3, 1917.

MICHAEL SMITH, or nrsnnn, ARI NA.

ROCK-DRILL.

Specification of Letters Patent.

Patented July 3, 1917.

Application filed September 28, 1916. Serial No. 122,613.

T '0 all whom it may concern:

Be it known that I, MICHAEL SMITH, a citizen of the United States, and a resident of Bisbee, in the county of Cochise and State of Arizona, have invented certain new and useful Improvements in Rock- Drills, of which the following is a specification.

My invention relates to rock drills of the type in which water is fed through the drill iron to the cutting end, and one of the main objects of the invention is to provide a constant supply of water to the reciprocating tappet and thence to the drill iron in a non-leakable manner and with a minimum of friction between the operative parts.

My invention includes a packing formed of a ring of flexible material of channel shape held in position by means of a me-' tallic perforated ring, said packing being held in its operative position by means of separable members of the housing of the tappet and the member of which likelyto become worn by rock cuttings is relatively small and inexpensive and readily replaced when worn.

My invention is fully described in the following specification, of which the accompanying drawings form a part, in which like characters refer to like parts in each of the views, and in which Figure 1 is a fragmentary longitudinal" central section taken through a rock drill and showing my invention applied thereto;

Fig. 2 is a section taken on the line 22' of Fig; 1; and Fig. 3 is an enlarged, detached, fragmentary, view of my improved packing.

Referring to the drawings, 4 represents,

the cylinder wherein a piston is reciprocated to strike a tappet 5 slidably arranged within a bushing formed of two members-6 and 7 held in operative relationship by means of a head 8 screw-threaded upon the member 6 and which member 6 is in turn screwthre'aded into the cylinder 4, said tappet impinging upon the inner end of a drill iron 9 havmg a bore 10 therethrough, the plston not being shown as it forms no part of this invention.

The tappet 5 is shouldered at 11 to limit inward movement thereof and its outward movement is limited by the head 8, and the bushing member 6 is of an increased diameter (interiorly) to receive the enlarged or shouldered portion of the tappet, as shown at 12, and is of greater diameter interiorly at 13 than at the portion 12 to receive the bushing member 7 in a slidable manner, the internal diameter of the member 7 equaling that of the portion 12 of the member 6 to serve as a bearing for the tappet in its reclprocation.

Arranged in the inner end of the enlarged internal portion 13 of the bushing member 6, and held therein by the member 7, is a packing ring 14 of'flexible material formed into channel shape with the open side inward toward the tappet against which it bears, said flexible ring 14 having an inlet 15 in register with a water feed passage 16 in the bushing member 6 and to which water is led from any source of supply, either at atmospheric or forced pressure.

The flexible ring 14 is held in its operative position or shape by means of a perforated metallic ring 17 also of substantially channeled formation with the open side outwardly allowing the water to enter thereinto from the inlet 15 and with its perforated side inwardly and extended through the open side of the flexible ring whereby the water in the metallic ring may pass to one or more longitudinally arranged channels 18 in the outer surface of the tappet.

The tappet channels 18 are of such length as to insure communication thereof with the perforations in the metallic ring 17 in any axial position of the tappet and, in view of the fact that the metallic ring is filled with water entirely around the tappet, a supply of water is assured to the tappet channels 18.

These channels 18 are connected with bores 19 leading to an axial bore 20 in the tappet and which last named bore connects with the bore 10 of the drill iron 9, and it will thus be seen that a constant supply of water, or of air under pressure if desired, is assured in the drill iron and therefore at its cutting end.

,The metallic ring 17 will preferably not touch the tappet but will force the leather or other material of the flexible ring against the tappet, thus reducing the friction between packing and tappet to a minimum and, if the bushing member 7 should become worn by rock cuttings entering the head 8 a new one may be expeditiously substituted'therefor and at low cost because of 1 the relatively small size of said member.

I may, if desired, make structural changes over the details shown and described, provided such changes do not depart from the spirit of the invention and come within the scope of the appended claims.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The combination in a rock drill adapted to a drill iron having an axial bore therethrough, a tappet having an axial and a lateral passage, and a bushing having a passage connecting the exterior with the interior thereof; of a packing consisting of a channeled ring of perforated flexible material having its open side toward said tappet lateral passage and its perforations toward said bushing passage, and a channeled ring MICHAEL SMITH.

Witnesses:

G. W. PRICKETT, GEORGE E'rz, Jr. 

